1. Field of the Invention
The present invention relates to a resist pattern formed by reducing thickness of the resist pattern at the time of patterning the resist pattern, an effective process for forming a resist pattern, a resist pattern thickness reducing material capable of forming a resist pattern and reduces thickness of the resist pattern beyond the limit of fineness attainable by a light exposure, and to a semiconductor device and process for manufacturing a semiconductor device utilizing a pattern by the resist pattern.
2. Description of the Related Art
In recent years, as integration further proceeds on semiconductor integrated circuits, LSIs(Large Scale Integrated Circuits) and VLSIs(Very Large Scale Integrated Circuits) have been put into practical use, and accompanying such trend of integration, a technology to form fine-pattern is being sought after. As a technology in forming fine patterns, conventionally, lithography is used. In lithography for instance, a substrate having a thin film thereon is covered with a resist film, the resist film is then selectively exposed and developed to form a resist pattern, followed by dry etching performed utilizing the resist pattern as a mask. Thereafter the resist pattern is removed to obtain a desired wiring pattern.
Here, in order to form fine wiring patterns, wavelength of an exposure light needs to be shortened, and a resist material which exhibits high resolution to the property of the light source of the exposure light needs to be developed. However, in order to shorten the wavelength of the exposure light, there is a need to modify a conventional development apparatus, hence it accompanies a large amount of cost. On the other hand, there is a persistent need to keep using a light exposure (that is, an exposure using a light) to maintain mass production even under fine pattern forming currently under progress.
An object of the present invention is to provide a resist pattern thickness reducing material capable of efficiently forming a resist pattern reduced in thickness which may suitably be used in a resist pattern forming.
Another object of the present invention is to provide a process for forming a resist pattern capable of forming a resist pattern finely formed beyond the limit of fineness attainable by a light exposure, and which may be used with a light source of the conventional light exposure device, and which exceeds in mass producibility.
Still another object of the present invention is to provide a resist pattern which is attainable by reducing thickness of a resist pattern.
Yet another object of the present invention is to provide a high performance semiconductor device which is attainable by utilizing the resist pattern.
And finally, still further object of the present invention is to provide a step for manufacturing a semiconductor device which may be used with a light source of the conventional light exposure device, and which is capable of mass producing a semiconductor device utilizing the resist pattern finely formed beyond the limit of fineness attainable by a light exposure of the light source.
When the resist pattern thickness reducing material is coated onto the resist pattern, portion of the resist pattern thickness reducing material which exists in the vicinity of an interface of the resist pattern impregnates into the resist pattern, thereby forming a mixing layer at an interface. The resist pattern obtained by removing the resist pattern thickness reducing material and the mixing layer, has a fine structure, since the thickness equivalent to the thickness of the mixing layer is removed.
In the process for forming the resist pattern of the present invention, after the resist pattern is formed, the resist pattern thickness reducing material is coated thereon. When the resist pattern thickness reducing material is coated, portion of the resist pattern thickness reducing material which exists in the vicinity of an interface of the resist pattern impregnates into the resist pattern, thereby forming a mixing layer at the surface of the resist pattern. Thereafter, by removing both the resist pattern thickness reducing material and the mixing layer, a finely formed resist pattern reduced in thickness equivalent to the thickness of the removed mixing layer is formed.
Since the resist pattern of the present invention is formed by the process for forming the resist pattern abovementioned, has a fine structure.
Since the semiconductor device of the present invention utilizes the resist pattern, exhibits high quality and high performance.
In the semiconductor manufacturing device of the present invention, after the resist pattern is formed on an underlayer, the resist pattern thickness reducing material is coated thereon. When the resist pattern thickness reducing material is coated, portion of the resist pattern thickness reducing material which exists in the vicinity of an interface of the resist pattern impregnates into the resist pattern, thereby forming a mixing layer at an interface. Thereafter, by removing both the resist pattern thickness reducing material and the mixing layer, a resist pattern having a fine structure reduced in thickness equivalent to the thickness of the removed mixing layer is formed. By using the resist pattern as a mask in performing patterning of the underlayer by etching, the manufacturing of the semiconductor showing high quality and high performance may be achieved.